At least not from the same browser? At least it doesn't appear that I have to log out of my work account on all my devices ... (that would imply: including my computer at work).

The procedure is:
if you want to access your personal blog and have a gmail interface at work:
close your work email tab in your browser
edit your blog
reopen your work email tab (from the history works in Firefox)

If you leave your blogspot tab open you can still access it after reopening your work email tab but you won't get the initial access to your personal blog if you have your work email tab open

I'm pretty sure the same isn't true for Google Drive/Sheets as I do access this from my personal account all the time while having a work email tab open - so, please Google, fix this for blogger - I do want access to both of my email accounts at the same time.